Hygienic heat exchanger

Abstract

A hygienic food product to food product heat exchanger (1). The heat exchanger (1) has an elongated and hollow housing (4), a metal tube plate (6) arranged at each of the opposite ends of the elongated housing (4) for defining a closed interior space (10) inside the elongated and hollow housing (4), a plurality of tightly spaced metal tubes (2) axially extending between the tube plates (2) with the ends of the tubes being received in correspondingly tightly spaced holes the tube plates (6) or with the lumen of the tubes being aligned with said correspondingly tightly spaced holes in the tube plates. The metal tubes (2) are sealingly secured to the metal tube plates (6) by a welding joint (20) on the inwardly facing side of the tube plates (6).

Description

[0001]The present disclosure relates to a hygienic food product to food product tubular type heat exchanger that is suitable for us in food processing applications, i.e. a heat exchanger that can be easily and regularly cleaned inside and outside by ordinary cleaning in place by e.g. rinsing with an acidic fluid.BACKGROUND ART[0002]Known food product tubular heat exchangers have a tube plate at each end of an elongated and typically cylindrical housing (shell) with a plurality of densely packed axial tubes extending between the two tube plates as a tube bundle. The ends of the tubes are received in corresponding through going holes in respective tube plates. During manufacturing of the heat exchanger the ends of the tubes are inserted into the holes and with a relatively tight fit and this relatively tight fit can be increased by rolling the inner side of the tubes so that the tube wall becomes thinner in the rolled area thereby tries to increase its diameter which causes the outer ...

AI Technical Summary

Benefits of technology

[0005]On this background, it is an object of this disclosure to provide a hygienic axial tube heat exchanger that can operate with liquid food products in the lumen of the tubes and also in the interior of heat exchanger that surrounds the tubes in order to provide a food product to food product heat exchanger, i.e. a heat exchanger that overcomes or at least reduces the drawbacks mentioned above.

[0006]This object is achieved by providing a hygienic food product to food product heat exchanger, the heat exchanger comprising: an elongated and hollow housing; a metal tube plate arranged at each of the opposite ends of the elongated housing for defining a closed interior space in the elongated and hollow housing; a plurality of tightly spaced metal tubes axially extending between the tube plates with the ends of the tubes being received in correspondingly tightly spaced holes in the tube plates or the lumen of the tubes being aligned with said correspondingly tightly spaced holes in the tube plates; wherein the metal tubes are sealingly secured to the metal tube plates by a welding joint on the inwardly facing side of the tube plates, whereby the welding joint extends along the complete circumference of a tube and provides for a smooth transition between the outer surface of a tube and the inwardly facing side of the tube plate.

[0014]The object above is also achieved by providing a method of manufacturing an axial tubular heat exchanger that comprises metal tube plates at each opposite end of an elongated heat exchanger housing and tightly spaced axial metal tubes extending between the tube plates, the method comprising inserting the ends of the tubes in corresponding holes in the tube plates or aligning the lumen of the tubes being with said correspondingly tightly spaced holes in the tube plates and creating a joint by welding between the tubes and the tube plates on the side of the tube plates that faces the interior of the elongated cylindrical housing for providing a smooth rounded transition between the outer surface of a tube and the inwardly facing side of said tube plate.

Problems solved by technology

However, in the field of hygienic heat exchangers, i.e. heat exchangers that are suitable for use with liquid food products and that come in direct contact with liquid food products it is of utmost importance to avoid sharp corners, crevices, fissures, pockets or other forms of recesses are difficult to rinse and sterilize and where food rests can remain thus risking that microorganisms start to flourish.

Therefore, in these type of heat exchangers food products can only be used in the lumen of the tubes and not in the interior of the elongated housing.

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